Rachel Noerdlinger (left) with Mayor Bill de Blasio and his wife Chirlane McCray.
James Messerschmidt

Now we know Rachel Noerdlinger wasn’t just a liar, she was a liar working for other liars to help tell lies.

Officially hired as First Lady Chirlane McCray’s chief of staff until she was forced out by scandal, Noerdlinger was in fact working as liaison to her old boss, Al Sharpton, for the entire de Blasio administration.

E-mails released just before the holiday weekend (in a classic effort to bury bad news) show that Noerdlinger regularly passed along official talking points to Sharpton — while also counseling the mayor on how to keep Sharpton happy.

After Sharpton’s incendiary rhetoric humiliated both Mayor de Blasio and Police Commissioner Bill Bratton at last July’s infamous press conference, she got City Hall to pull back from exposing Sharpton as — what else — a liar.

Sharpton had claimed he didn’t know until the last minute that he’d share the dais with Bratton. In fact, Noerdlinger had ­e-mails showing he’d been told so. But she counseled City Hall not to tell the press — because the mayor and the reverend had supposedly made peace in the meantime.

Yep: Sharpton used a mayoral event to burn the mayor and the police commissioner, then lied about key details. But his lies went unknown, because his old employee ran interference.

Noerdlinger was finally forced out last fall in the wake of multiple embarrassments — notably, news that she was living with an anti-cop ex-con and had failed to admit the relationship on official disclosure forms.

The whole tissue of lies began when the mayor opted to give Sharpton his own taxpayer-funded mole at City Hall. But the greatest outrage, we fear, is that not a single one of the liars learned his or her lesson.